With xfce 4.14, each panel sets an icon size for all of the components within it. The timeout plugin currently does not change the size of its icon as the panel icon size changes. It should size its icon according to the panel icon size. I have submitted a pull request to the github mirror for xfce4-time-out-plugin with a potential implementation of a resolution for this issue; you can see the pull request at https://github.com/xfce-mirror/xfce4-time-out-plugin/pull/1
Glen Whitney referenced this bugreport in commit 4d21f4027bb549ae51dbe14c80079b17212476b9 Make time out plugin respect panel icon size (Bug #15839) https://git.xfce.org/panel-plugins/xfce4-time-out-plugin/commit?id=4d21f4027bb549ae51dbe14c80079b17212476b9
Thanks for the patch, as this function is new on 4.14 I added some macros to keep the old code for 4.12 and older versions. By the way, this is one of the few plugins that were ported to gtk3, if you are interested, there in a WIP (stalled) attempt to port it here: https://github.com/Skunnyk/xfce4-time-out-plugin
Thanks so much for incorporating this into master, and for adding the conditionals on the XFCE version, I would not have realized how to do that. I truly wish I had the time and skills to take up the GTK2 -> GTK3 port of this, as I would really like to be able to style this plugin with gtk.css, but I am afraid I just do not have any clear picture of the differences between gtk2 and gtk3 or what's involved in porting. I have noticed that unlike most all other plugins, the time-out.h header is not decorated with a bunch of macros like G_OBJECT_DECL and the like (that I am not clear on the function of). I imagine, perhaps incorrectly, that a proper port to gtk3 would involve supplying those, and that's rather daunting -- I don't know at all how to make new G_OBJECTs or how to use these (apparently code-generating) macros. I am just able to find the bits of code that are doing the thing that I think isn't quite right, and tweak them.
Okay, no problem :)